What to call (and not to call) the Jamboree

On first mention write "The 26th World Scout Jamboree Poland 2027". Afterwards it can be shortened to "WSJ Poland 2027", simply "Poland 2027" or "the Jamboree". 
The formal name of the Jamboree is "the 26th World Scout Jamboree Poland 2027". We will use this rarely.

When referencing other Jamborees use this format: Country + year + World Scout Jamboree.
It is common to use the country name and year as shorthand for event names.